1 /* bitrotate.h - Rotate bits in integers
2 Copyright (C) 2008 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Simon Josefsson <simon@josefsson.org>, 2008. */
19 #ifndef _GL_BITROTATE_H
20 #define _GL_BITROTATE_H
24 /* Given an unsigned 32-bit argument X, return the value corresponding
25 to rotating the bits N steps to the left. N must be between 1 and
27 static inline uint32_t
28 rotl32 (uint32_t x, int n)
30 return ((x << n) | (x >> (32 - n))) & 0xFFFFFFFF;
33 /* Given an unsigned 32-bit argument X, return the value corresponding
34 to rotating the bits N steps to the right. N must be between 1 to
36 static inline uint32_t
37 rotr32 (uint32_t x, int n)
39 return ((x >> n) | (x << (32 - n))) & 0xFFFFFFFF;
42 /* Given an unsigned 16-bit argument X, return the value corresponding
43 to rotating the bits N steps to the left. N must be between 1 to
45 static inline uint16_t
46 rotl16 (uint16_t x, int n)
48 return ((x << n) | (x >> (16 - n))) & 0xFFFFFFFF;
51 /* Given an unsigned 16-bit argument X, return the value corresponding
52 to rotating the bits N steps to the right. N must be in 1 to 15
54 static inline uint16_t
55 rotr16 (uint16_t x, int n)
57 return ((x >> n) | (x << (16 - n))) & 0xFFFFFFFF;
60 #endif /* _GL_BITROTATE_H */